Characterisation of pile salting with sodium replaced mixtures of salts in dry-cured loin manufacture

Salting, one of the fundamental operations in Spanish cured loin manufacturing, is essential to preserve the product throughout its processing and storage. However, elevated blood pressure has been identified to be the major adverse effect associated with increased sodium intake. The partial replacement of NaCl with other chloride salts such as KCl, CaCl₂ and MgCl₂ has been proposed as a possible strategy to reduce the sodium content of these products. The aim of this study was to determine the salting time needed to reach the same chloride content as commercial dry-cured loins and, to characterise the first step in dry-cured loin production (salting), in loins salted with sodium partial replaced salts. The results indicated a reduction in the salting time when using KCl as NaCl substitute and an increase in the salting time when adding CaCl₂ and MgCl₂ to the mixture. Further studies need to be done in order to fully understand the influence of these low sodium mixtures of salts on the following manufacturing steps and the final quality characteristics of the product.     

Use of a D-optimal mixture design to estimate the effects of diverse chloride salts on the growth parameters of Lactobacillus pentosus

The effects of NaCl, KCl, CaCl₂, and MgCl₂ and their mixtures on the ionic strength (IS) of the medium and the growth parameters of Lactobacillus pentosus were studied by means of a D-optimal mixture experimental design with constrains (total salt concentration ≤ 9.0%, wt/vol) and the generalized z-value. The IS was linearly related to the concentrations of the diverse salts and its increase, for similar concentrations of salts, followed the order MgCl₂ > CaCl₂ > NaCl > KCl. Within the experimental region, the lag phase duration (λ) was mainly affected by NaCl and CaCl₂ and the interaction KCl with MgCl₂. The maximum specific growth rate (μ_max) decreased as NaCl (the highest effect), CaCl₂, and MgCl₂ increased (regardless of the presence or not of previous NaCl); low KCl concentrations had a stimulating effect on μ_max, but its overall effect showed a similar trend to the other salts. The maximum population reached (N_max) was the least affected parameter and decreased as NaCl and CaCl₂ concentrations increased regardless of the presence of the other salts. The equations that expressed the growth parameters as a function of the diverse chloride salts, within the limits assayed, were developed and the corresponding z- and harmonic Z-values were estimated.     

Biochemical and sensory changes in dry-cured ham salted with partial replacements of NaCl by other chloride salts

The reduction of the content of sodium chloride in dry-cured ham was studied in to prevent the problems related to high sodium intake (i.e. the hypertension). One of the possibilities to reduce the sodium content is the partial replacement of sodium chloride by mixtures of potassium, magnesium and calcium chloride salts. The effect of two salting formulations (formulation II: 50% NaCl-50% KCl and formulation III: 55% NaCl, 25% KCl, 15 CaCl₂ and 5 MgCl₂) on the protease activity through the dry-curing process and on the sensory characteristics of the final product was evaluated and compared to those of control hams (formulation I, 100% NaCl). Sensory attributes were all affected in the hams containing CaCl₂ and MgCl₂ while hams containing 50% KCl and NaCl (formulation II) were better valued, except for the attribute taste probably due to the potassium contribution to bitter taste.     

Influence of sodium replacement on the salting kinetics of pork loin

The partial replacement of sodium chloride by other salts has been proposed as a possible strategy to reduce the sodium content of cured meat products. Nevertheless, there is very little knowledge as regards the influence of salts other than sodium chloride on salting kinetics.The aim of this study was to evaluate the effect brought about by substituting sodium chloride with potassium, calcium and magnesium chloride on the salting kinetics of dry cured loins. The results showed very important changes in the salting pattern depending on the type of salts. Partial substitution of sodium affected both water and ion transport during the salting process. The presence of KCl decreased water loss while CaCl₂ and MgCl₂ had the opposite effect. However, replacement of up to 50% NaCl by KCl had no significant effect on the salting kinetics in the case of the control formulation. Calcium and magnesium cations penetrated with difficulty into the muscle remaining in the brine formed during the pile salting process. Moreover, the presence of calcium and magnesium cations considerably reduced the sodium and potassium content of the salted loin.     

Effect of chloride salts on protein extraction and interfacial protein film formation in meat batters

Six comminuted chicken breast meat mixes and six meat batters were made with isoionic NaCl (25 g kg^?1), MgCl₂, CaCl₂, KCl, LiCl (IS = 0.43) and 15 g kg^?1 NaCl (IS = 0.26). The quantity and type of proteins extracted and used for interfacial protein film (IPF) formation was determined and related to batter stability. The monovalent salts produced IPF which differed in individual protein content between salts but which all contained significantly larger amounts of protein (P < 0.01) than those using divalent salts. MgCl₂ extracted more protein than CaCl₂ and produced a different protein profile in the IPF. However, MgCl₂ formed unstable raw batters whereas CaCl₂ did not. In addition, a simple, rapid method for extracting and quantifying proteins from meat batters was developed to assist in direct determination of the actual soluble protein uptake by the fat phase during comminution.     

Effect of sodium,potassium, calcium and magnesium chloride salts on porcine muscle proteases

This study is focused on the effect of sodium chloride alternative salts (KCl, MgCl₂ and CaCl₂) on porcine muscle proteases (cathepsins, dipeptidylpeptidases and aminopeptidases). In general, KCl exerted a very similar effect to NaCl for all the studied enzymes, while the effect of divalent salts (CaCl₂ and MgCl₂) was more pronounced. Cathepsins, dipeptidyl peptidase III, dipeptidyl peptidase IV and alanyl aminopeptidase activities were strongly inhibited by all the chloride salts especially by divalent ones. Dipeptidyl peptidase II and leucyl aminopeptidase were little affected and methionyl aminopeptidase was only inhibited by divalent salts. Dipeptidyl peptidase I was strongly activated by low concentrations of the chloride salts except NaCl. Arginyl aminopeptidase was activated by NaCl and KCl and low amounts of MgCl₂, while CaCl₂ showed a strong inhibitory effect. This is very important as these enzymes play important roles in dry-cured meats and their activity is, in general, regulated by sodium chloride. Thus, reductions in the sodium concentration with subsequent increases of other alternative cations may have relevant consequences on enzyme activity that should be taken into account when processing dry-cured meats.     

Nucleotides and their degradation products during processing of dry-cured ham, measured by HPLC and an enzyme sensor

The aim of this work was to study how nucleotide degradation during the processing of dry-cured ham is affected when using three types of salting (100% NaCl; 50% NaCl and 50% KCl; 55% NaCl, 25% KCl, 15% CaCl₂ and 5% MgCl₂). Divalent salts in the salting mixture depressed the breakdown rate from the beginning of the process (salting and post-salting) up to the ripening stage (7 months) when the inosine (Ino), hypoxanthine (Hx) and xanthine (X) concentrations matched for the three treatments. The evolution of Hx and Hx + X were analysed by HPLC and an enzyme sensor, respectively, during processing. Time and temperature conditions during the curing time did not affect Hx stability. The usefulness of the enzyme sensor was confirmed and it is a practical tool to determine Hx + X in dry-cured ham, as an index of minimum curing time. A good correlation between enzyme sensor and HPLC data was observed.     

The effect of brine composition and pH on the yield and nature of water-soluble proteins extractable from brined muscle of cod (Gadus morhua)

Fillets of Atlantic cod (Gadus morhua) were held for 36 h in brines of pH 6.5 and 8.5, respectively, containing various combinations of NaCl, KCl, MgCl₂ and CaCl₂. Proximate analyses and chloride content were determined. Soluble muscle protein extracted in distilled water and protein released into the brine following salting was determined by SDS–PAGE. The soluble fraction was not affected by the presence of divalent salts or KCl in the brines, but it was affected by the initial pH. Both actin and myosin heavy chain (MHC) were released in pH 6.5 brines after immersion of the fish. On the other hand, an initial pH of 8.5 did not favour the release of these proteins. There was a smaller variety of remaining soluble proteins in salted muscle with an initial pH of 6.5, than with 8.5. However, this effect of the lower pH was offset to the extent that the ionic strength of the brine was higher.     

Effects of Chloride Salts on Appearance, Palatability, and Storage Traits of Flaked and Formed Beef Bullock Restructured Steaks

Restructured steaks made with 0.5 or 1.0% KCl, 0.5% MgCl₂ and 0.5% CaCl₂ were more desirable and darker red in raw color than blends formulated with 0.5 or 1.0% NaCl. Visual properties of raw steaks containing 0.5 or 1.0% chloride salt were scored higher than the control (no salt added) in 14 of 16 orthogonal contrast mean comparisons. Steaks made with 1.0% CaCl₂ or MgCl₂ were rated lower than the control in flavor desirability and overall satisfaction ratings. Control, 0.5 or 1.0% NaCl or 0.5 and 1.0% KCl steaks were not different in juiciness, tenderness, flavor desirability or overall satisfaction ratings. Steaks made with chloride salts were rancid after 70 days frozen storage. Results showed steaks made with KCl were superior to steaks formulated with CaCl₂ or MgCl₂.     

Effect of soaking with hydrogen peroxide and carbonate/bicarbonate buffer solutions on chemical composition and protein extractability of desalted cod

Cod salted with various combinations of NaCl, KCl, MgCl₂ and CaCl₂ were soaked for the first 24 h with a 0.2 M carbonate buffer solution (pH 9.5) or for the first 5 h with 1% hydrogen peroxide (pH 7.16). Chloride, ions and ash content in muscle were measured during the soaking process. After soaking, the composition of soluble muscle protein extracted in NaCl 0.86 M was determined by SDS-PAGE. The divalent, cation content was not affected by the salting and soaking processes. The protein extractability was low, especially when H₂O₂ was used. The use of alkaline buffer solution produced better protein functional quality. When the alkaline solution was used for soaking, the soluble fraction was constituted of a larger variety of proteins. Actin was soluble only when MgCl₂ and KCl were used for salting and the alkaline solution for soaking. The use of carbonate/bicarbonate buffer solution for soaking could therefore be useful to improve the functional quality of muscle protein of desalted cod.     

Water sorption and time-dependent crystallization behaviour of freeze-dried lactose-salt mixtures

Water sorption properties of freeze-dried lactose, lactose/CaCl₂, lactose/NaCl, lactose/MgCl₂, and lactose/KCl mixtures in their molar ratio of (9:1) were investigated. Brunauer-Emmett-Teller (BET) and Guggenheim-Anderson-de Boer (GAB) models were used to model water sorption properties. Water is known to function as a plasticizer, depressing the glass transition and facilitating crystallization. Crystallization in the present study resulted in loss of sorbed water from lactose. The crystallization of pure lactose and lactose/salt mixtures was observed at RVP?44.0% within 24 h. At RVP?54.4% water contents were higher in lactose/CaCl₂ and lactose/MgCl₂ mixtures than in pure lactose, lactose/NaCl, and lactose/KCl.Water content in pure lactose after crystallization was ?5.0%, suggesting that lactose crystallized as a mixture of α-lactose monohydrate and various anhydrous forms of α/β-lactose crystals. Anhydrous lactose/CaCl₂ and lactose/MgCl₂ had higher glass transition temperatures than lactose, but other salts (NaCl and KCl) with lactose gave lower glass transition than amorphous lactose. It seems that bivalent salts in mixtures with lactose gave a higher T_g than smaller monovalent ions. Salts delayed lactose crystallization. The effect on lactose crystallization was highest with calcium chloride (CaCl₂) and lowest with potassium chloride (KCl). It seems that different salts interacted with lactose to different extents. For water sorption, GAB model gave a better fit than BET model. Water sorption and time-dependent crystallization properties of lactose/salt mixtures should be considered in manufacturing and storage of dairy-based dehydrated materials.     

The influence of serum phase on the whipping time of unhomogenised cream

The objective of this study was to investigate how the properties of the serum phase, including ionic strength, protein content and specific milk salts, influence the whipping time of unhomogenised cream. This study showed that decreasing the protein content of the serum phase in cream resulted in shorter whipping time. However, addition of UF permeate to both deproteinated and proteinated creams indicated that other components than the protein fraction also influence whipping time of unhomogenised cream. Increasing the ionic strength by addition of NaCl, KCl and CaCl₂ decreased whipping time, with the largest effect being found for CaCl₂. A further increase in ionic strength by addition of NaCl and KCl resulted in an unfavourable effect on whipping time, whereas a pronounced effect, with shorter whipping times, was found for addition of CaCl₂.     

Rheological and Gelation Properties of Meat Batters Prepared with Three Chloride Salts

The gelation and rheological properties of poultry meat emulsions prepared with three chloride salts (NaCl, KCl, MgCl₂) and 50/50 mixtures of the above salts at isoionic strength (IS = 0.42) were studied. The relationship between shear rate and shear stress for the different raw meat emulsions was found to be nonlinear and followed Bingham pseudoplastic behavior. The yield stress for the emulsion containing only MgCl₂ was significantly lower as compared to all the other treatments. The highest rigidity modulus values obtained during cooking were observed in the NaCl + MgCl₂ treatment followed by the NaCl + KCl, NaCl and KCl. The emulsion containing MgCl₂ only broke down at the initial stages of cooking, exhibiting the destabilizing effect of the magnesium cation.     

Protein Extractability of Turkey Breast and Thigh Muscle with Varying Sodium Chloride Solutions as Affected by Calcium, Magnesium and Zinc Chloride

Ground turkey breast and thigh muscle were extracted with various NaCl solutions with or without added CaCl₂, MgCl₂, or ZnCl₂ (0.05%). Protein solubility was increased by CaCl₂ and decreased by ZnCl₂ in each muscle type. At 4% NaCl, MgCl₂ increased thigh myosin solubility by 30%, compared to the control, whereas CaCl₂ had no effect. At 2% and 4% NaCl, breast myosin was not affected by MgCl₂ or CaCl₂. Myosin was not detected for either muscle type when ZnCl₂ was used. All three salts increased breast actin solubility but only MgCl₂ increased thigh actin solubility. The CaCl₂ resulted in the highest overall protein solubility and MgCl₂ resulted in the highest thigh myosin and actin solubility at 4% NaCl.     

A study on the implications of NaCl reduction in the fermentation profile of Conservolea natural black olives

This study examined the impact of different mixtures of NaCl, KCl, and CaCl₂ on the fermentation profiles of Conservolea natural black olives. Five different combinations of chloride salts were investigated, namely (i) 8% NaCl (control treatment), (ii) 4% NaCl and 4% KCl, (iii) 4% NaCl and 4% CaCl₂, (iv) 4% KCl and 4% CaCl₂, and (v) 2.6% NaCl-2.6% KCl-2.6% CaCl₂. The changes in the microbial association (lactic acid bacteria, yeasts, Enterobacteriaceae), pH, titratable acidity, organic acids, volatile compounds, and mineral content in olive flesh were analyzed. Results demonstrated that all salt combinations led to vigorous lactic acid processes based on the obtained values of pH (3.9-4.2) and titratable acidity (0.70-0.86 g lactic acid per 100 ml brine). Organoleptic evaluation was a critical factor in the acceptability of the final product. Increasing concentrations of CaCl₂ or a combination of KCl and CaCl₂ rendered the product bitter with low acceptability by the taste panel. Only one combination of chloride salts (4% NaCl and 4% KCl) could finally produce olives with lower sodium content and good organoleptic attributes. The results of this study could be employed by the Greek table olive industry in an attempt to produce natural black olives with less sodium without affecting the traditional taste of fermented olives in order to meet consumers’ demand for low sodium dietary intake.     

Generation of volatile compounds in Brazilian low-sodium dry fermented sausages containing blends of NaC1, KC1, and CaC12 during processing and storage

Brazilian dry fermented sausages with different salt contents were manufactured: control (2.5% NaCl), 50% salt reduced (1.25% NaCl, F1), 50% replaced by KCl (1.25% NaCl and 1.25% KCl, F2), 50% replaced by CaCl₂ (1.25% NaCl and 1.25% CaCl₂, F3), and 50% replaced by KCl and CaCl₂ (1.25% NaCl, 0.625% KCl and 0.625% CaCl₂, F4). Changes in the composition of volatile compounds were studied during processing (0, 7, and 19 days) and storage (30, 60, and 90 days). Neither reduction nor replacement of NaCl by KCI affected the volatile compounds produced during the manufacturing process, and both increased the volatile compounds from carbohydrate fermentation and amino acid degradation during storage. The addition of CaCl₂ improved the generation of hexanal and (E)-hept-2-enal and other volatiles from lipid oxidation during processing and storage. After 90 days of storage, the control sample showed an increase in the generation of volatile compounds from lipid oxidation.     

Effect of NaCl reduction and replacement on the growth of fungi important to the spoilage of bread

The effect of NaCl and various NaCl replacers (CaCl₂, MgCl₂, KCl and MgSO₄) on the growth of Penicillium roqueforti and Aspergillus niger was evaluated at 22 °C. In addition, challenge tests were performed on white bread to determine the consequences of NaCl reduction with or without partial replacement on the growth of P. roqueforti. From the results obtained it can be concluded that at equivalent water phase concentrations the isolates exhibited differing sensitivities to the salts evaluated with NaCl and MgCl₂ having the greatest inhibitory action on the growth of A. niger and P. roqueforti, respectively. MgSO₄ had the least antifungal activity. At equivalent molalities, CaCl₂ had in general the largest antifungal activity. Although the water activity (a_w) lowering effects of the compounds studied play a large role in explaining the trends observed, at equivalent water phase concentrations MgCl₂ was found to have a smaller inhibitory effect on A. niger than that expected from its a_w depressing effect. The challenge tests revealed that no difference occurred in the growth of P. roqueforti on standard white bread, bread with 30% less NaCl and bread in which 30% of the NaCl has been partially replaced by a mixture of KCl and Sub4Salt. These results are of importance in assessing the possible microbiological consequences of NaCl reduction or replacement in bread and similar bakery products.     

ANTIMICROBIAL EFFECTS OF SODIUM AND OTHER IONS IN FOODS: A REVIEW1

Salt or sodium chloride (NaCl) is a common ingredient in many processed foods, and especially in cured meats. In addition to flavoring and functional contributions, NaCl is believed to play an important antimicrobial role in these products. The antimicrobial activity of NaCl is reviewed in light of currrent calls for a reduction of Na⁺ in the human diet due to health reasons, and the possible replacement of NaCl in processed foods with chloride salts of other ions (i.e. KCl, MgCl₂, CaCl₂). Factors interacting with NaCl and complicating the nature of the preservative system in processed foods are examined; recent work with alternative chloride salts is summarized; complex solute-water activity interactions are highlighted; and, several important factors are considered in relation to the antimicrobial effects of NaCl and the possibility of its replacement with other chloride salts.     

Effects of Mechanically Separated Beef with Various Chloride Salts in Restructured Beef Steaks

The effects of various chloride salts (NaCl, MgCl₂, KCl or 65% NaCl + 35% KCl) in combination with mechanically separated beef (MSB at 0, 10 or 20%) on the quality of restructured steaks formulated from bullock chucks were determined. As level of MSB increased, objectionable connective tissue, flavor desirability and overall palatability decreased and off-flavors increased. The development of oxidative rancidity during frozen storage was not affected by MSB level and MSB had little effect on textural traits. NaCl and NaCl + KCl treated steaks received superior flavor and overall palatability ratings over steaks containing MgCl₂ or KCl. Oxidative rancidity developed faster in steaks containing NaCl than the other salt types. Partial replacement (35%) of NaCl with KCl resulted in restructured steaks with sensory properties equal to and storage life superior to steaks with NaCl alone.